Not applicable.
The present invention relates to an image printing apparatus. In particular, the present invention relates to an image printing apparatus and to a microcontroller for an image printing apparatus.
Recently, digital printing technology has been proposed as a suitable replacement for traditional camera and photographic film techniques. The traditional film and photographic techniques rely upon a film roll having a number of pre-formatted negatives which are drawn past a lensing system and onto which is imaged a negative of a image taken by the lensing system. Upon the completion of a film roll, the film is rewound into its container and forwarded to a processing shop for processing and development of the negatives so as to produce a corresponding positive set of photos.
Unfortunately, such a system has a number of significant drawbacks. Firstly, the chemicals utilized are obviously very sensitive to light and any light impinging upon the film roll will lead to exposure of the film. They are therefore required to operate in a light sensitive environment where the light imaging is totally controlled. This results in onerous engineering requirements leading to increased expense. Further, film processing techniques require the utilizing of a xe2x80x9cnegativexe2x80x9d and its subsequent processing onto a xe2x80x9cpositivexe2x80x9d film paper through the utilization of processing chemicals and complex silver halide processing etc. This is generally unduly cumbersome, complex and expensive. Further, such a system through its popularity has lead to the standardization on certain size film formats and generally minimal flexibility is possible with the aforementioned techniques.
Recently, all digital cameras have been introduced. These camera devices normally utilize a charge coupled device (CCD) or other form of photosensor connected to a processing chip which in turn is connected to and controls a media storage device which can take the form of a detachable magnetic card. In this type of device, the image is captured by the CCD and stored on the magnetic storage device. At some later time, the image or images that have been captured are down loaded to a computer device and printed out for viewing. The digital camera has the disadvantage that access to images is non-immediate and the further post processing step of loading onto a computer system is required, the further post processing often being a hindrance to ready and expedient use.
The Applicant is presently developing technology that is consumer based and is therefore intended to have an extremely high turnover rate. However, this technology relates to relatively complex image processing and printing techniques. At present, devices that carry out such processes are relatively expensive and are therefore not intended to be high turnover devices. It follows that, at present, the components that make up such a device are usually standard and are capable of being programmed to carry out specific tasks. This permits manufacturers to avoid the necessity of having to fabricate task-specific microcontrollers and microprocessors.
An example of a prior art device is shown in FIG. 1A. This is a schematic block diagram of a print head 1a and a control system 2a for the print head 1a. As can be seen, the control system 2a has a printer driver component 3a and a microprocessor/microcontroller 4a that are separate from each other. This allows the microprocessor/microcontroller 4a to be provided as a standard component that is then pre-programmed to carry out specific tasks.
It follows that it is counter-intuitive for a microcontroller to be provided that incorporates printer interface or driver circuitry, since this would mean that the microcontroller would have to be manufactured to suit a specified task.
Applicant has, however, conceived the present invention in an attempt to simplify component requirements for an image printing control system. Applicant believes that it is advantageous to have such a purpose-built microcontroller when applied to high turnover devices such as those that the Applicant envisages marketing.
A microcontroller is an integrated chip that includes, on one chip, all or most of the components needed for a controller. A microcontroller is what is known as a xe2x80x9csystem on a chip.xe2x80x9d A microcontroller can typically include the following components:
CPU (central processing unit);
RAM (Random Access Memory);
EPROM/PROM/ROM (Erasable Programmable Read Only Memory);
bus interface/s;
timers; and an
interrupt controller.
An advantage of microcontrollers is that by only including the features specific to the task (control), cost is relatively low. A typical microcontroller has bit manipulation instructions, easy and direct access to I/O (input/output) data, and quick and efficient interrupt processing. Microcontrollers are a xe2x80x9cone-chip solutionxe2x80x9d which reduces parts count and design costs. The fact that a microcontroller is in the form of a single chip allows the manufacture of controlling devices to take place in a single integrated circuit fabrication process.
According to a first aspect of the invention, there is provided an image printing apparatus that comprises
a print head for printing images; and
a microcontroller that comprises
a wafer substrate;
processor circuitry that is positioned on the wafer substrate;
print head interface circuitry that is positioned on the wafer substrate and is connected between the processor circuitry and the print head, the print head interface circuitry being configured to facilitate communication between the processor circuitry and the print head; and
bus interface circuitry that is discrete from the print head interface circuitry and is connected to the processor circuitry so that the processor circuitry can communicate with devices other than the print head via a bus
According to a second aspect of the invention, there is provided an image printing apparatus that comprises
a page width print head that is the product of an integrated circuit fabrication technique and which includes a plurality of nozzle arrangements, each nozzle arrangement defining a micro electromechanical device that is capable of being actuated to eject ink from a nozzle chamber of the nozzle arrangement; and
a microcontroller that comprises
a wafer substrate;
processor circuitry that is positioned on the wafer substrate;
print head interface circuitry that is positioned on the wafer substrate and is connected between the processor circuitry and the print head, the print head interface circuitry being configured to facilitate communication between the processor circuitry and the print head; and
bus interface circuitry that is discrete from the print bead interface circuitry and is connected to the processor circuitry so that the processor circuitry can communicate with devices other than the print head via a bus.
According to a third aspect of the invention, there is provided a microcontroller for an image printing apparatus, the microcontroller comprising
a wafer substrate;
processor circuitry that is positioned on the wafer substrate;
print head interface circuitry that is positioned on the wafer substrate and is connected between the processor circuitry and the print head, the print head interface circuitry being configured to facilitate communication between the processor circuitry and the print head; and
bus interface circuitry that is discrete from the print head interface circuitry and is connected to the processor circuitry so that the processor circuitry can communicate with devices other than the print head via a bus.
The invention is now described, by way of example, with reference to the accompanying drawings. The specific nature of the following description should not be construed as limiting in any way the broad nature of this summary.